Now that I am not allowed to play my horn for about a month; {eye surgery}
I would like to expound upon a few helpful points if I may.....

Firstly, if players would get to know their body as well as their instruments,
they would be able to play with much greater ease and much less stress
and strain thereby increasing endurance. I have observed that a great many
musicians play by unconsciously forcing the body to conform to the demands
of the instrument. It's rare that I see it done the other way around, namely
in using your body in a way where playing your instrument becomes an "extension"
of the proper actions of the body..

By doing it this way you would more likely get the feeling of
ONENESS with your instrument which most players would want I'm sure. One
of the obstacles probably being in the education of musicians. If you know
your body and use it as part and parcel of your instrument you would
play with much greater ease and less stress and strain.. If you do it the
other way around [which many many musicians do] the body will act out of
habitually accommodating the difficulties of the instrument... The result
will be stress, strain, fatigue all which in turn will become chronic....
all of which could be avoided. To overcome these problems means to
be aware of what movements you can do to help facilitate your instrument
! !

You want to make your posture FLUID and ADAPTIVE... get away from a
fixed and bent position. Let your body flow with your horn the same as
you want your music to FLOW. Get away from that stiff military stance..

Shift your weight. As an ex. the cellist has to shift weight through
the hips and turn them left and right..... We on our horns should be going
into the horn when we are going up on an ascending line. Straight ahead.
GO OUT ...straight OUT. I see so many players crunching, coming down into
their necks , into the body, pulling the horn down and in . If the music
is going up from say G ,A, B, high C, D, E , F high G etc. your body should
be taking the weight by going out into the horn in a fluid manner and flowing
back as you descend.

Don't fight the horn's resistance, go WITH it and of course always keeping
your air flow continual NEVER adjusted. This kind of movement of the hips
and spine will result in integrating your body and your instrument which
in turn will improve playing and reducing stress. Your body is well designed
to do these functions .When you become aware of doing this and knowing
what you are doing and how it helps your playing --a natural biofeedback.
It's a natural movement of the body. Once you bring this process of your
body working with the horn into awareness, improvement will follow and
the harmful effects of old stressful habits will dissipate. Think of your
body and your horn as ONE.